Theorem 3exbidv 1792

Description: Formula-building rule for 3 existential quantifiers (deduction rule). (Contributed by NM, 1-May-1995.)

Hypothesis

Ref	Expression
3exbidv.1	|- ( ph -> ( ps <-> ch ) )

Assertion

Ref	Expression
3exbidv	|- ( ph -> ( E. x E. y E. z ps <-> E. x E. y E. z ch ) )

Distinct variable groups:   ph, x   ph, y   ph, z

Allowed substitution hints:   ps( x, y, z)   ch( x, y, z)

Proof of Theorem 3exbidv

Step	Hyp	Ref	Expression
1		3exbidv.1	. . 3 |- ( ph -> ( ps <-> ch ) )
2	1	exbidv 1748	. 2 |- ( ph -> ( E. z ps <-> E. z ch ) )
3	2	2exbidv 1791	1 |- ( ph -> ( E. x E. y E. z ps <-> E. x E. y E. z ch ) )

Syntax hints:   -> wi 4   <-> wb 103   E.wex 1422

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1377  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-4 1441  ax-17 1460  ax-ial 1468

This theorem depends on definitions:  df-bi 115

This theorem is referenced by:  ceqsex6v  2652  euotd  4037  oprabid  5589  eloprabga  5643  eloprabi  5874